Effect of UV-C radiation treatment on microbial load and antioxidant capacity in hot pepper, fennel and coriander

Ultraviolet (UV-C) radiation treatment effects on microbial load, total phenolic content, total flavonoids and antioxidant activities of three spices, hot pepper, fennel and coriander, were investigated. Spice samples were placed 15 cm from the UV-C source for 20, 40 and 60 min to provide doses of 3.5, 7.0 and 10.4 kJ m−2 inside the package. UV-C treatments significantly (P < 0.05) reduced the microbial load and Salmonella and E. coli were eliminated in all samples. The total phenolic content and total flavonoids greatly increased with an increasing exposure of UV-C in all samples (P < 0.05). Moreover, the antioxidant activity of the spices was enhanced after the UV-C treatment. These results indicate that UV-C treatment can maintain the quality of dried spices and be applied as an effective preservative method in food industries.